The region’s blood bank is calling on people to donate blood to make up for critical shortages caused by chilly weather and the loss of potential donors sickened by flu and cold.

“A normal dip in donations during the holidays is expected, but in the first 10 days of January we’re already down 800 units below what is needed,” said James AuBuchon, president and CEO of Bloodworks Northwest (formerly Puget Sound Blood Center).

“Regular donors are delaying coming in because of illness, while extreme winter weather and treacherous road conditions in southwest Washington and Oregon have hampered donors in those communities,” he said in a news release.

Illness and severe weather elsewhere in the U.S. are straining blood supplies nationwide.